Spanish tax authorities say they are investigating allegations of tax irregularities involving soccer player Lionel Messi after documents released by an international probe of offshore accounts.

Messi's family released a statement Monday denying wrongdoing and threatened to sue media outlets that released the information linking the Argentine player to accounts in Panama.

The Barcelona star was among those named in reports by international media who received a vast trove of data and documents leaked from a law firm based in Panama.

Last year, Spanish authorities charged Messi and his father with three counts of tax fraud for allegedly defrauding Spain's tax office of 4.1 million euros ($4.4 million) in unpaid taxes from 2007-09. They will stand trial in late May and face nearly two years in prison if found guilty.